ML20125A661
| ML20125A661 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/07/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19319A602 | List: |
| References | |
| NUDOCS 7908090684 | |
| Download: ML20125A661 (2) | |
Text
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4 UNITED STATES
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NUCLEAR REGULATORY COMMIS$10N WASHINGTON, D. C. 20805 g
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.16 TO FACILITY OPERATING LICENSE NO. NPF-3 THE TOLEDO EDISON COMPANY AND THE CLEVELAND ELECTRIC ILLUMINATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346 Introduction By letter dated October 23, 1978, the Toledo Edison Company (TECO or the licensee) requested an amendment to Facility Operating License No. NPF-3 for the Davis-Besse Nuclear Power Station, Unit No.1 (Davis-Besse1). The amendment would change the Technical Specifications (TS) concerning the ReactorCoreSafetyLimit(RCSL) curve,theReactor Protection System Instrumentation Trip Setpoints (RPSITS), and the max-imum Reactor Coolant Hot Leg Temperature for Departure from Nucleate Boiling (DNB) margin.
The proposed TS changes are a result of a corrected analysis of the Loss of Flow Accident (LOFA) transient which applies to the as-measured one Reactor Coolant Pump Coastdown curve.
Background
The present TS concerning the RCSL curve, the RPSITS and the maximum Reactor Coolant Hot Leg Temperature for DNB margin resulted from the LOFA analysis using the Babcock and Wilcox (B&W) RADAR code, an NRC-acceptable code-for the LOFA transient.
In that analysis, the licensee applied a designed one RCP coastdown curve which is not as steep as the actual measured one RCP coastdown curve. The anilysis was made to support the changes required as a result of the removal of the Burnable Poison Rod Assemblies (BPRAs), and all but two of the Orifice Rod Assemblies (0 ras)(Amendment No.11 dated June 16,1978). After the BPRAs and ORAs were removed, the licensee discovered an error in the B&W analysis of the LOFA transient. The error concerned the use of the as-designed one RCP coastdown curve instead of the as-measured one RCP coastdown curve. The licensee reported this by letter dated July 28, 1978, and took administrative actions to reduce the setpoints for the Reactor Protection System and apply more conservative operating limits.
The proposed amendment would implement these new setpoints for the Reactor Protection System and the more conservative operating limits into the TS.
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,. - Evaivation We have reviewed the licensee's submittal. We find the proposed changes to the TS to be more conservative than the present TS and find that the proposed changes preserve the DNB ratio (DNBR) margin for the loss of flow transient. We conclude that the proposed changes to the TS provide no decrease in the safety margin and are therefore acceptable.
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Environmental Consideration We have determined.that the amen'dment does not authorize a change in effluent types or. total amounts nor an increase in power level Having and will not result in any significant environmental impact.
made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4), that an environmental impact statement, or neaative declaration and environ-mental impact appraisal need not be p.repared in connection with the issuance of this amendment.
Conclusion'
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We have concluded, based on the considerations discussed above. that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the ' health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities wi.11 be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: Juie 7, 1979 e-
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